World Physical Features and Natural Regions

1. The world map frame: continents, oceans, latitudes and the highest peaks

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• Continent counts (Class 6, Oceans and Continents): there can be four, five, six or seven. The usual seven, from largest to smallest, are Asia, Africa, North America, South America, Antarctica, Europe and Australia. Asia has about 30% of the world's land and Africa about 20%.
• Eurasia: Europe and Asia are one landmass. By custom they are split along the Urals, the Ural river, the Caspian, the Caucasus and the Turkish Straits.
• Oceans, largest first: Pacific, Atlantic, Indian, Southern, Arctic.
• The Equator crosses Ecuador, Colombia, Brazil, Gabon, the Republic of Congo, DR Congo, Uganda, Kenya, Somalia and Indonesia.
• The Tropic of Cancer crosses Mexico, the Sahara states, Egypt, Saudi Arabia, the UAE, Oman, India, Bangladesh, Myanmar, China and Taiwan.
• The Tropic of Capricorn crosses Chile, Argentina, Paraguay, Brazil, Namibia, Botswana, South Africa, Mozambique, Madagascar and Australia. Check the exact country counts in an atlas.
• Rivers that cross a line twice: the Congo crosses the Equator, the Limpopo crosses the Tropic of Capricorn and the Mahi crosses the Tropic of Cancer.
• Seven Summits (the highest peak on each continent):

Continent	Peak	Height and place
Asia	Everest (Sagarmatha, Chomolungma)	8,849 m (China-Nepal survey, 2020; NCERT: 8,848 m)
South America	Aconcagua	about 6,961 m, Argentina, Andes
North America	Denali	about 6,190 m, Alaska; renamed Mount McKinley by US order in 2025 (verify current)
Africa	Kilimanjaro	about 5,895 m, Tanzania; a volcano standing alone, not part of a range
Europe	Elbrus	about 5,642 m, Caucasus, Russia (Mont Blanc, about 4,806 m, if the Caucasus is left out)
Antarctica	Vinson Massif	about 4,892 m
Australia-Oceania	Puncak Jaya / Kosciuszko	about 4,884 m, New Guinea / about 2,228 m, mainland Australia

• Indian climbers (Class 6, Landforms and Life): Bachendri Pal was the first Indian woman to climb Everest (1984). Arunima Sinha climbed Everest in 2013 and then all seven summits. She was the first woman amputee (a person who has lost a limb) to do so.

2. Mountains and plateaus of the world

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• Young fold mountains are tall, have sharp peaks and are still rising. They form where plates push into each other. There are two belts:
• Alpine-Himalayan belt: Atlas, Pyrenees, Alps, Apennines, Dinaric Alps, Carpathians, Caucasus, Taurus, Zagros, Elburz, Hindu Kush, Karakoram and Himalaya.

• Circum-Pacific belt: Rockies and Andes.

• Andes: the world's longest continental range. It runs about 7,000 km down western South America through seven countries. It formed as the Nazca Plate slid under (subducted beneath) South America. It has volcanoes, the high Altiplano with Lake Titicaca, and Aconcagua (about 6,961 m).

• Caucasus Mountains: they lie between the Black and Caspian Seas, across Russia, Georgia, Armenia and Azerbaijan. They are often taken as part of the Europe-Asia boundary. Elbrus (about 5,642 m), a dormant volcano, is Europe's highest peak.
• Other mountain types:
• Old, rounded mountains: Appalachians, Urals, Scandinavian highlands, Great Dividing Range, Drakensberg.
• Block mountains: Vosges, Black Forest, Sierra Nevada.

• Volcanic peaks: Kilimanjaro, Fuji, Etna.

• Pamir Knot ("Roof of the World", Bam-i-Dunya): it lies mainly in Tajikistan, with Afghanistan's Wakhan Corridor. The Hindu Kush, Karakoram, Kunlun and Tian Shan meet here, and the Himalaya joins through the Karakoram.

• Hindu Kush: it runs about 800 km through central Afghanistan into northern Pakistan, west of the Pamirs. Its highest peak is Tirich Mir (about 7,700 m). The Salang Pass crosses it. The Khyber Pass lies just south, in the Spin Ghar range. Together these passes made the old Central Asia-India route.
• Tibetan Plateau: the world's largest and highest plateau.
• Size: it averages about 4,500 m high and is about 2,500 km from east to west, between the Himalaya and the Kunlun.
• "Third Pole": the Indus, Sutlej, Brahmaputra (Yarlung Tsangpo), Yangtze, Mekong and Yellow rivers start here.
• Monsoon link: its strong summer heating helps drive the Asian monsoon.

• In the news: China's Medog (Motuo) dam on the Yarlung Tsangpo (verify current).

• Other plateaus: Deccan (old, volcanic, black soil), East African (gold and diamonds, from Class 6, Landforms and Life), Ethiopian, Brazilian, Anatolian, Iranian, Arabian, Mongolian, Colorado (Grand Canyon), Columbia (lava), Bolivian Altiplano, Patagonia and the Laurentian Shield.

• Plains: North European, West Siberian (Ob basin), Great Plains, Amazon, North China, Mesopotamia and Indo-Gangetic (about 40 crore people, per Class 6, Landforms and Life).
• Great Rift Valley: it runs from the Red Sea through Ethiopia to Mozambique.

3. Great rivers and their basins

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• Nile: the world's longest river (about 6,650 km). It flows north to the Mediterranean.
• Sources: the White Nile leaves Lake Victoria at Jinja, Uganda. The Blue Nile leaves Lake Tana in Ethiopia.
• They meet at Khartoum, Sudan.

• Egypt depends on it almost entirely (Aswan High Dam, 1970; Lake Nasser).

• Grand Ethiopian Renaissance Dam (GERD): Africa's largest hydropower dam, on the Blue Nile near the Sudan border. It was inaugurated in 2025. Egypt and Sudan fear it will cut their water (verify current).

• Congo River: Africa's second-longest river.
• It is the world's deepest river (over 220 m deep in places) and second by discharge (the amount of water it carries).
• It crosses the Equator twice and drains the Congo Basin rainforest.

• Its Inga Falls have large hydropower potential.

• Victoria Falls (Mosi-oa-Tunya): on the Zambezi, on the Zambia-Zimbabwe border. It is about 1.7 km wide and 108 m high. Downstream are the Kariba and Cahora Bassa dams.

• Other African rivers: the Niger makes a great bend and has an inland delta in Mali. The Limpopo crosses the Tropic of Capricorn twice.
• Famous falls elsewhere: Angel (Venezuela, the highest), Niagara (Canada-USA) and Iguazu (Argentina-Brazil).
• Amazon: it flows east from the Peruvian Andes across Brazil to the Atlantic. It carries more water than any other river, about one-fifth of all river water reaching the oceans.
• Other American rivers: Mississippi-Missouri (bird's-foot delta), Colorado (Grand Canyon, Hoover Dam), St Lawrence, Mackenzie, Yukon, Parana (Itaipu Dam) and Orinoco.
• Danube: Europe's second-longest river, after the Volga. It flows from Germany's Black Forest to the Black Sea. It runs through or along ten countries, more than any other river, and passes four capitals: Vienna, Bratislava, Budapest and Belgrade.
• Rhine and Volga: the Rhine is Europe's busiest inland waterway (Rotterdam). The Volga drains into the Caspian.
• Tigris-Euphrates river system: both rivers rise in Turkey and flow through Syria and Iraq. They join as the Shatt al-Arab (on the Iran-Iraq border) and enter the Persian Gulf.
• Their valley, Mesopotamia, was a cradle of civilisation.

• Turkey's GAP project and Ataturk Dam cause water disputes with Syria and Iraq.

• Mekong: it rises in Tibet and flows through China (where it is called the Lancang), Myanmar, Laos, Thailand, Cambodia and Vietnam to the South China Sea.

• Chinese dams upstream hurt fisheries and Cambodia's Tonle Sap, a lake whose flow reverses each monsoon.

• The Mekong River Commission (1995) leaves China out. China leads the Lancang-Mekong Cooperation (2016). India works through Mekong-Ganga Cooperation (2000).

• Other Asian rivers: Yangtze (Asia's longest; Three Gorges Dam), Huang He ("China's sorrow"), Amur, Irrawaddy and Salween.

• The Ob, Yenisei and Lena flow north into the Arctic. They flood in spring because their southern headwaters thaw first.

4. Lakes and inland seas

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• Great Lakes of North America: five connected freshwater lakes on the USA-Canada border. Use the mnemonic HOMES (Huron, Ontario, Michigan, Erie, Superior).
• Michigan lies wholly in the USA.
• Superior is the largest freshwater lake by area.
• Niagara Falls lies between Erie and Ontario.

• They drain through the St Lawrence River. The St Lawrence Seaway (1959) lets ocean ships reach the interior.

• Caspian Sea: the world's largest inland water body (about 371,000 sq km).

• It is a saltwater lake about 28 m below sea level.
• It is bordered by Russia, Kazakhstan, Turkmenistan, Iran and Azerbaijan. The Volga supplies most of its water.
• It has oil, gas and sturgeon (the fish that gives caviar).

• The Aktau Convention (2018) settled its legal status. Its water level is falling (verify current).

• Lake Baikal: a rift lake in southern Siberia.

• It is the deepest (about 1,642 m) and oldest (about 25 million years) lake in the world.
• It holds about one-fifth of the Earth's unfrozen surface fresh water.

• It became a World Heritage Site in 1996 and is home to the nerpa seal.

• Aral Sea: on the Kazakhstan-Uzbekistan border. It was once the world's fourth-largest lake.

• Cause: Soviet projects took water from the Amu Darya and Syr Darya rivers for cotton.
• Effect: the sea has shrunk by about 90% since the 1960s, leaving a toxic desert, the Aralkum.

• Partial recovery: Kazakhstan's Kok-Aral dam (2005) has partly revived the North Aral.

• Lake Victoria: Africa's largest lake and the world's largest tropical lake. It is shared by Uganda, Kenya and Tanzania and is the main source of the White Nile. Invasive (non-native) Nile perch and water hyacinth have harmed native fish.

• Lake Tanganyika: a rift-valley lake shared by Tanzania, DR Congo, Burundi and Zambia. It is the world's longest freshwater lake and the second deepest, after Baikal.
• Lake Chad: a shallow Sahel lake shared by Chad, Cameroon, Niger and Nigeria. It has shrunk by about 90% since the 1960s because of drought and irrigation. This has made poverty and conflict (Boko Haram) worse.
• Also: Titicaca (Peru-Bolivia, about 3,812 m, the highest large navigable lake), Balkhash (half fresh, half salty) and Lake Volta (Ghana, a reservoir).

5. Deserts of the world and the Sahel

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• Why deserts form (four causes):
• Sinking air under the subtropical highs: Sahara, Arabian, Thar, Kalahari, Australian.
• Cold currents along west coasts: Atacama, Namib.
• Inland areas far from the sea: Gobi, Taklamakan, Karakum.

• Rain shadows (dry land behind mountains that block rain-bearing winds): Patagonia behind the Andes, the Great Basin behind the Sierra Nevada.

• Hot and cold deserts (Class 6, Landforms and Life): the Sahara and Thar are hot. The Gobi is cold. Antarctica is sometimes called a desert.

• Sahara: the world's largest hot desert (about 9 million sq km).
• It stretches across North Africa from the Atlantic to the Red Sea.
• It has sand seas (ergs), stony plains (regs), the Ahaggar and Tibesti mountains, and the Qattara Depression.

• It was green about 6,000 years ago.

• Other deserts:

• Hot: Arabian (Rub al-Khali, the largest continuous sand sea), Kalahari (San people; Okavango inland delta), Australian (Great Victoria, Great Sandy, Gibson, Simpson), Mojave (Death Valley), Sonoran.

• Cold or mid-latitude: Gobi (China-Mongolia), Taklamakan, Karakum, Kyzylkum, Patagonian.

• Atacama Desert: in northern Chile, the driest non-polar place on Earth.

• Causes: the cold Humboldt (Peru) Current and the Andean rain shadow.
• Resources: copper, lithium (the "lithium triangle" with Argentina and Bolivia, where India's KABIL is interested; verify current) and nitrates.

• Its clear skies host major observatories.

• Namib Desert: along the Atlantic coast of Namibia, thought to be the oldest desert. The cold Benguela Current keeps it dry but brings fog that keeps beetles and the Welwitschia plant alive. Its dunes are among the tallest, and the Namib Sand Sea is a World Heritage Site (2013).

• Sahel: the semi-arid (partly dry) belt along the Sahara's southern edge, from Senegal and Mauritania to Sudan and Eritrea.
• It gets 200-600 mm of rain a year and faces repeated drought (worst in 1967-77), desertification (good land turning into desert) and conflict.

• Mali, Burkina Faso and Niger formed an Alliance of Sahel States outside ECOWAS (verify current).

• Great Green Wall: an African Union plan launched in 2007 to restore 100 million hectares of damaged land from Senegal to Djibouti by 2030. It is behind target (verify current). India's own land pledge under UNCCD is 26 million hectares by 2030.

6. Natural regions I: rainforests, savannas, monsoon lands, taiga and tundra

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• The natural-region idea (Herbertson, 1905): places with a similar climate have similar plants, animals and ways of life. This means each Koeppen climate type can be read as a landscape.
• Equatorial (Af) forest:
• Climate: hot and wet all year.
• Vegetation: dense evergreen forest in layers, with hardwoods such as mahogany and ebony. The soils are poor because rain washes nutrients out.

• People and economy: the Mbuti and Yanomami; shifting cultivation (clearing a forest patch, farming it, then moving on) and rubber and oil-palm plantations.

• Amazon rainforest: the largest tropical rainforest, about 5.5 million sq km.

• It is mostly in Brazil and shared by nine countries and territories.
• Clearing for cattle and soy, and fires, may push parts of it past a tipping point (a point of no return) into savanna.

• Diplomacy: the Amazon Cooperation Treaty Organization (1978); COP30 at Belem (2025).

• Congo Basin rainforest: the second largest. It spreads over DR Congo, the Republic of Congo, Cameroon, Gabon, the Central African Republic and Equatorial Guinea. Its Cuvette Centrale is the largest tropical peatland (wet land made of half-rotted plants that stores carbon).

• Tropical grasslands of the world (Aw): grass with scattered trees between the rainforests and the deserts. They have one wet and one dry season, and fire and grazing keep them open.
• African savanna (Serengeti; wildebeest migration; Maasai herders).
• Llanos (Venezuela and Colombia).
• Campos and Cerrado (Brazil; now a soy frontier).

• Northern Australia.

• Monsoon lands (Am): deciduous forest (trees that shed their leaves in the dry season), rice and dense populations.

• Taiga: the world's largest land biome (a large natural zone of similar plants and animals).
• It is a belt of conifers (pine, spruce, fir, larch) across northern North America, Scandinavia and Siberia, about 50-70°N (Dfc, Dwc).

• Economy: lumbering, pulp and fur. Warming is bringing more wildfires.

• Tundra (ET): mosses, lichens and dwarf shrubs on permafrost (ground that stays frozen all year).

• People: the Inuit, the Sami (reindeer herding), the Nenets and the Yakuts.

• Economy today: oil and gas at Prudhoe Bay and Yamal.

• Other regions: China type (Cfa: rice, tea, silk), British type (Cfb: dairying, fishing) and Laurentian.

7. Natural regions II: temperate grasslands and Mediterranean lands

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• Temperate grasslands of the world: they lie in mid-latitude continental interiors.
• Climate and soil: 25-75 cm of rain, mostly in summer, cold winters and fertile black chernozem soil.
• Why few trees: low rain, frost, fire and grazing.
• Economy (Class 12, Primary Activities): extensive commercial grain farming. Farms are big and machine-run, giving low yield per hectare but high yield per worker. Ranching (large-scale cattle or sheep farming) is common too.

Grassland	Where	Key facts
Prairies	interior USA and Canada, east of the Rockies	wheat and maize; opened by trans-continental railways; Chinook wind
Pampas	Argentina and Uruguay, around the Rio de la Plata	wheat and beef; South America's densest rail network
Steppes	Ukraine through southern Russia and Kazakhstan to Mongolia	wheat exported via the Black Sea; home of pastoral nomads; Soviet Virgin Lands campaign (1950s)
Velds	South African plateau; high veld about 1,200-1,800 m around Johannesburg and Pretoria	maize, wheat, merino sheep; Witwatersrand gold
Downs	south-eastern Australia, mainly the Murray-Darling basin	wheat, merino sheep, artesian wells
Canterbury Plains	east of New Zealand's South Island, in the rain shadow of the Southern Alps	grain and sheep (Canterbury lamb)

• Why they matter: droughts or wars here move world food prices. Examples are the Ukraine war (2022) and the Dust Bowl (US Great Plains drought, 1930s).
• Trap: the Prairies and Steppes are temperate. The Savanna, Llanos and Campos are tropical.
• Mediterranean lands (Cs):
• Where: around the Mediterranean, central California, central Chile, the Cape region of South Africa and south-western Australia.
• Climate: hot, dry summers and mild, rainy winters.
• Vegetation: drought-resistant scrub (maquis, chaparral, fynbos).
• Economy: olives, citrus, grapes and wine (the "orchard lands of the world"), winter wheat and tourism.
• Rising problems: summer wildfires and water stress.

8. Straits and chokepoints

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A chokepoint is a narrow sea passage that a large share of world shipping must pass through.

Strait	Joins	Between
Strait of Hormuz	Persian Gulf – Gulf of Oman and Arabian Sea	Iran – Oman (Musandam)
Bab-el-Mandeb (about 30 km wide)	Red Sea – Gulf of Aden	Yemen – Djibouti and Eritrea
Strait of Malacca (about 800 km long)	Andaman Sea – South China Sea	Malay Peninsula – Sumatra
Mozambique Channel (about 400 km at its narrowest)	arm of the Indian Ocean	Mozambique – Madagascar
Strait of Gibraltar (about 14 km wide)	Atlantic – Mediterranean	Spain – Morocco
Bosphorus	Black Sea – Sea of Marmara	runs through Istanbul, dividing Europe and Asia
Kerch Strait	Sea of Azov – Black Sea	Russia's Taman Peninsula – Crimea
Taiwan Strait (about 130-180 km wide)	East China Sea – South China Sea	Taiwan – mainland China
Bering Strait (about 82 km wide)	Pacific – Arctic	Russia's Chukotka – Alaska
Drake Passage	Atlantic – Pacific	Cape Horn – Antarctic Peninsula

• Hormuz: about one-fifth of the world's oil passes through it, including much of India's crude oil and LPG. Iran-related tensions keep threatening it (verify current).
• Bab-el-Mandeb: Houthi attacks from late 2023 forced many ships around the Cape of Good Hope. This raised the cost of India's trade with Europe. The Indian Navy deployed under Operation Sankalp (verify current).
• Malacca: China's main oil route, which is why its dependence is called the "Malacca dilemma". It lies near India's Andaman and Nicobar Islands. Ships can avoid it through the Sunda and Lombok straits. The Mozambique Channel is on the Cape route, near Agalega.
• Gibraltar: the only natural link between the Atlantic and the Mediterranean. British Gibraltar is on the north shore and Spanish Ceuta on the south.
• Turkish Straits: the Bosphorus and the Dardanelles, joined by the Sea of Marmara. The Montreux Convention (1936) lets Turkey block warships in wartime, as it did after Russia invaded Ukraine in 2022.
• Kerch: Russia's Crimean Bridge (2018) crosses it.
• Bering: the International Date Line runs between the two Diomede islands.
• Drake Passage: the Antarctic Circumpolar Current flows through it. The Strait of Magellan is the sheltered alternative.
• Others: Dover, Korea, Torres, Bass, Cook, Davis and Florida. Canals belong to the world-transport-communication note. The Palk Strait and the Ten Degree and Nine Degree Channels belong to the India notes.

9. Seas and gulfs in the news

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• Persian Gulf: a shallow arm of the Indian Ocean between Iran and the Arabian Peninsula.
• Eight countries border it: Iran, Iraq, Kuwait, Saudi Arabia, Bahrain, Qatar, the UAE and Oman.

• It holds huge oil and gas reserves, opens through Hormuz and has millions of Indian workers.

• Red Sea: a narrow sea formed as the African and Arabian plates pulled apart (rifting).

• It links to the Mediterranean through the Suez Canal and to the Gulf of Aden through Bab-el-Mandeb.

• The Gulfs of Suez and Aqaba lie on either side of Sinai.

• Gulf of Aden: an arm of the Arabian Sea between Yemen and Somalia. The Indian Navy has run anti-piracy patrols here since 2008, and piracy came back in 2023-24.

• Horn of Africa: Somalia, Ethiopia, Eritrea and Djibouti. This peninsula guards the Gulf of Aden and Bab-el-Mandeb.
• Djibouti hosts China's first overseas base (2017).

• Landlocked Ethiopia's 2024 sea-access deal with Somaliland caused tension (verify current).

• Black Sea: bordered by Turkey, Bulgaria, Romania, Ukraine, Russia and Georgia. It links to the Mediterranean through the Bosphorus and Dardanelles.

• Rivers such as the Danube, Dnieper and Dniester make it low in salt.
• Its deep water has no oxygen and is full of hydrogen sulphide.

• It is a theatre of the Russia-Ukraine war. The Black Sea Grain Initiative ran from July 2022 to July 2023.

• Baltic Sea: now almost ringed by NATO members, after Finland joined (2023) and Sweden joined (2024).

• South China Sea: bordered by China, Taiwan, the Philippines, Malaysia, Brunei, Indonesia and Vietnam.
• In July 2016 an arbitral tribunal under UNCLOS (the UN law of the sea) rejected China's "nine-dash line" claim (Philippines v. China). China does not accept the ruling.

• India backs freedom of navigation, and ONGC Videsh has oil blocks off Vietnam.

• Spratly and Paracel Islands: small islands, reefs and shoals in the South China Sea.

• The Spratlys are claimed wholly by China, Taiwan and Vietnam, and partly by the Philippines, Malaysia and Brunei.
• The Paracels have been held by China since 1974 and are claimed by Vietnam and Taiwan.

• China has built artificial islands on some reefs. Scarborough Shoal and Second Thomas Shoal see clashes (verify current).

• Gulf of Guinea: the north-eastern tropical Atlantic off West Africa, where the Equator meets the Prime Meridian (0°, 0°). It is rich in oil (Niger Delta) and is a piracy hotspot (Yaounde Code of Conduct, 2013).

10. Islands and the Indian Ocean map

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• Largest islands, in order: Greenland, New Guinea, Borneo, Madagascar, Baffin, Sumatra, Honshu, Great Britain.

• Borneo is shared by Indonesia (Kalimantan, with the new capital Nusantara), Malaysia and Brunei.

• Madagascar: the world's fourth-largest island, off south-east Africa across the Mozambique Channel. It broke away from India about 88 million years ago. Most of its wildlife, like lemurs, is found nowhere else.

• Divided or disputed islands:
• Divided: Hispaniola (Haiti and the Dominican Republic), Timor, Ireland, Cyprus.

• Disputed: Kuril (Russia-Japan), Senkaku or Diaoyu (Japan-China), Falklands or Malvinas (UK-Argentina).

• Hotspot and science islands: Hawaii, Galapagos (Ecuador) and Iceland (on the Mid-Atlantic Ridge).

• Indian Ocean island chain:
• Island countries: Mauritius, Seychelles, Comoros, Maldives, Sri Lanka.
• French: Reunion, Mayotte, Kerguelen. Australian: Cocos (Keeling), Christmas Island. Yemeni: Socotra.

• Indian: Andaman and Nicobar, Lakshadweep.

• Agalega Islands: two small islands of Mauritius, about 1,100 km north of the main island. An India-built airstrip and jetty opened there in 2024. They help connectivity and maritime surveillance (watching the seas).

• Chagos Archipelago: central Indian Ocean.
• Britain separated it from Mauritius in 1965.
• The ICJ advisory opinion (2019) and UNGA resolution 73/295 asked Britain to return it.
• A 2025 UK-Mauritius treaty gives sovereignty (ownership) to Mauritius. Britain keeps the US-UK base on Diego Garcia on a 99-year lease (verify current ratification).

• India supported Mauritius.

• India's policy frame: SAGAR (2015), widened as MAHASAGAR (2025) (verify current).

11. The polar regions: Greenland, Antarctica, the Arctic and India's stations

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• Greenland: the world's largest island.
• It is an autonomous (self-governing) territory of Denmark, between the Arctic and Atlantic Oceans. Class 6, Oceans and Continents says it equals India's ten largest states put together.
• Its ice sheet is second only to Antarctica's. If it all melted, sea level would rise about 7 m, and it is already losing ice.

• It has rare earths, and the USA showed interest in buying it in 2019 and 2025 (verify current).

• Arctic Council: set up by the Ottawa Declaration (1996).

• Members: the eight Arctic states (Canada, Denmark, Finland, Iceland, Norway, Russia, Sweden, USA), with indigenous groups as permanent participants.

• India has been an observer since 2013. Work with Russia was paused after 2022 (verify current).

• Himadri station: India's first Arctic station (2008), at Ny-Alesund in Norway's Svalbard archipelago. NCPOR, Goa runs it. It supports India's Arctic Policy (2022), and India is a party to the Svalbard Treaty (1920).

• Antarctica: it holds about 90% of the world's ice and about 70% of its fresh water. The Transantarctic Mountains split it into East and West Antarctica.
• Antarctic Treaty:
• Signed in 1959 and in force from 1961.
• Keeps Antarctica for peace and science, bans military activity and nuclear tests, and freezes seven countries' land claims.
• The Madrid Protocol (1991, in force 1998) bans mining.

• India joined in 1983 and became a consultative (voting) party the same year. It passed the Indian Antarctic Act 2022 and hosted the 46th Consultative Meeting at Kochi (2024).

• Indian Antarctic research stations (Indian Antarctic Programme since 1981):

• Dakshin Gangotri (1983, now a supply base).
• Maitri (1989, Schirmacher Oasis).
• Bharati (2012, Larsemann Hills).

• Maitri II is planned (verify current).

• Thwaites Glacier ("Doomsday Glacier"): a West Antarctic glacier about the size of Florida.

• Cause: warm seawater melts it from below.

• Effect: it is melting fast. If it collapses, sea level could rise about 65 cm and the West Antarctic Ice Sheet could become unstable.

• Recent signs: Antarctic sea ice hit record lows in 2023 (verify current). The Arctic is warming nearly four times faster than the world as a whole, which is opening the Northern Sea Route.

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Exam angles

Prelims — high-yield facts and traps

• Straits: Hormuz (Iran-Oman), Bab-el-Mandeb (Yemen-Djibouti/Eritrea), Malacca (Malaya-Sumatra), Gibraltar (Spain-Morocco), Kerch (Azov-Black Sea), Bering (Pacific-Arctic), Drake (Cape Horn-Antarctica).
• Countries bordering water bodies: Caspian 5 · Black Sea 6 · Persian Gulf 8 · Lake Victoria 3 · Tanganyika 4 · Chad 4. Lake Michigan lies wholly in the USA.
• Nile chain: White Nile from Lake Victoria (Jinja) + Blue Nile from Lake Tana → meet at Khartoum → Mediterranean.
• Other river facts: the Tigris and Euphrates join as the Shatt al-Arab. The Danube crosses 10 countries and passes 4 capitals. The Mekong crosses 6 countries. Victoria Falls is on the Zambezi.
• Rivers crossing a line twice: the Congo (Equator) and the Limpopo (Capricorn).
• Superlatives:
• Lakes: Baikal is the deepest and oldest, the Caspian the largest inland water body, Superior the largest freshwater lake by area.
• Land: the Tibetan Plateau is the highest and largest plateau, the Andes the longest range, Greenland the largest island, the taiga the largest land biome.

• Deserts: the Atacama is the driest non-polar place, the Namib the oldest, the Sahara the largest hot desert.

• Grasslands: Prairies (North America), Pampas (Argentina-Uruguay), Steppes (Eurasia), Velds (South Africa), Downs (Australia), Canterbury (New Zealand).

• TRAP: "The Llanos and Campos are temperate grasslands" is FALSE. They are tropical.
• TRAP: "Kilimanjaro is part of the East African range" is FALSE. It is an isolated volcano. Elbrus, not Mont Blanc, is usually taken as Europe's highest peak.
• TRAP: "The Aral Sea shrank mainly because of natural drought" is FALSE. River water was diverted for cotton.
• Polar: Antarctic Treaty 1959 (India joined 1983) · Madrid Protocol bans mining · Indian stations Dakshin Gangotri, Maitri, Bharati and Himadri (Ny-Alesund, Svalbard) · India an Arctic Council observer since 2013.
• In-the-news islands: Chagos (Diego Garcia), Agalega (Mauritius), Spratly and Paracel, Kuril, Svalbard.

Mains — GS-I themes

1. Indian Ocean chokepoints (Hormuz, Bab-el-Mandeb, Malacca) and India's maritime security: how the Red Sea crisis raised Indian trade costs.
2. Shrinking lakes (Aral, Chad) as case studies of human-made environmental change and its social costs.
3. Shared rivers and conflict or cooperation: the Nile and GERD, the Mekong and Chinese dams, the Tigris-Euphrates. What they teach about the Brahmaputra and Indus.
4. Natural regions: how climate shapes vegetation, economy and settlement, from equatorial to tundra.
5. The Arctic and Antarctica in a warming world: resources, sea routes, sea-level risk and India's polar policy.
6. Desertification and restoration: the Sahel, the Great Green Wall and India's land-degradation-neutrality pledge.

Current-affairs hooks

• Shipping attacks in the Red Sea, Gulf of Aden and Hormuz, and Indian Navy deployments (verify current).
• China-Philippines incidents in the South China Sea; Taiwan Strait drills (verify current).
• Ratification of the Chagos treaty; India's projects in Mauritius and Seychelles (verify current).
• GERD and the Nile dispute; Chinese dams on the Mekong and Yarlung Tsangpo (verify current).
• Amazon deforestation data and forest finance (TFFF) after COP30 at Belem (verify current).
• Greenland's status, Thwaites findings, Antarctic sea ice and India's new polar stations (verify current).
• Black Sea security and grain exports; the Kerch Strait and Crimean Bridge (verify current).